Automatic expansion-valve.



PATENTE@ MAY 14, 1907.

EDDY. AUTOMATIC EXPANSIG VALVE.

UNITED STATES PATENT OFFICE.

ARTHUR H. EDDY, OF W'INDSOR, CONNECTlCUT, ASSIGNOB. OF OEE-HALF TOCHARLES E. SHEPARD, OF HARTFORD, CONNEHCUT.

AUTOMATC EXPANSIN-VALVE.

Speciicatcn of Itters Patent. Applicaties led January i 1956i Serial No.297,079.

Patented May 14, 1907.

llowing is a specification.

This invention relates to an expansion valve which operatestoautomaticall control the low of refri erating fluid to t e expansioncoil in the re rigeratmg compartment according to the temperature of t eatmosphere in the com artment or temperature of the liqud`in W ch theexpansion coil may be submer ed. T e object of thisinventon is toprovide a simple, durable and compact valve of this nature which issensitive and which is easily regulated so that it will o crate at thenecesy sary times to cause an e cient action of the relrigeratin aparatus.

In the ern o ment of the invention which Ais illustrated by the accomanying drawing the valve is normally held c osed by the pressure of thererigerating iiuid on a diaphraY located on the expansion side ofthevaltlf and the valve is opened by the tension of a spring which isarranged in o position to the ressure of the daphr t e action of 4the `ahragm' as affectedlxy1 the fluid ressure or y the spring pressure beingme ied by the action of an expansionv dia hragm located between thepressure diap a and the valve and arranged to be expan ed and contractedby the expansion and contraction of alluid which is exposed in a thermicreceptacle placed as desired in the compartment the temperature of whichis to be refri erated.

he accompanying drawing shows .a central vertical section of a valvethat embodies the invention. l

Over the end of the casing 1 and held in Vplace by the frame 2 of thisvalve'is a diaphra 3. The expansion chamber 4 above this 'aphra isconnected by a passage 5 with the out et 6 which is adapted to beconnected with a pipe that leads to the expansion coil in thecompartment which is to be refrigerated.l The expansion chambercommunicates through the port 7 in the block 8 with the pressure chamber9 that connected by the passage 10 with the inlet 11 tvhich is adaptedto be connected with a pipe from a receptacle containing the supply ofrefrigerating fluid, usually ammonia, in a liquid state and underpressure.

On the upper surface of the block about the port is a valve seat 12 andmovable towar and from this 'seat is a valve 13. The valve stem 32 maybe guided in its movement so that the valve will seat properly by prongs14 extending from the head 15 at its lower end Aand by extending itsupper end into a lrecess 16 in the cap 17. A'spring 18 thrusts betweenthe block and the head of the stem so as to hold the head against theexpansion diaphragm 19 which is located in the expan sion chamber. The sring which is shown between the block an the valve stein head need notbeV employed if the valve stem is attached permanently to theexpansiondiaphrssm! Between the pressure diaphragm and the expansiondiaphra is a pad 20 and below theV ressure diap ra 1s a pad 2l.

s ir spring 22 thrustlng between thescrew puff 23 and a Washer 24 withlegs 25 tends to ol the lower pad in osition and a s idershaped springV26 held y a sleeve 27, t e position of which is determined by theadjustment of the screw plug 28, presses the lower pad and the diaphragmupwardly with the requisite force. I

A Atube 29 extends through the plugs, sleeve, pads and the pressurediaphragm, and opens into the ex ansion diaphra in. This tube isconnected Ey a pipe 30 Wit a closed receptacle 3i which is designed tobe laced in a brine tank or in the atmosphere in the compartment cooledby the expansion of the rerigerating fluid in the expansion coil. Thisreceptacle, pipe, tube and the exparisien diaphragm are preferablyiilled full of an expansible fluid such as alcohol. The expansion andcontraction of this fluid due to the various changes of temperature towhich the receptacle 1s subjected in the conipartment being cooled,causes an expansionV and contraction of the expansion diaphragm and thisof course causes a variation of the length of the connection between thepres- 'sure diaphragm and the valve.

The refrigerating fluid pressure on the pressure diaphragm tends tocontract the expension diaphragm and force down the pressure diaphragmand allowV the valve to be IOO closed gainst its seat by the valve stems ring. The spring plressure that opposes theiluid pressure on t ediaphr m tends to move the valve from its seat. n this case the springpressure and the expansion of the expansion diaphragm tend to open thevalve and the spring and the Huid pressure in the expansion chamber andthe contraction of the expansion diaphragm tend to close the valve.Cnnsequentl the times of open` and clos` 0 of the va ve and the extentof the opening i e ends on the relations of the amount of ownwardpressure on the pressure diaphragm due to the fluid pressure, thepressure of the valve stem spring, the condition oil the expansiondiaphragm due to in ternal pressure, and the amount of u ward pressuredue to the force of the springs elow the ressure diaphragm.

there is not sufiieient flow of refrigerating fluid to keep down thetemperature in the compartment being cooled the temperature will riseand the rlsing temperature will cause an expansion of the regulatinfluid and consequently an expansion of t e expansion diaphragm. Thlslengthens the distance between the pressure dlaphragm and the valve andconse uently if the ressure in the ex ansion cham er is normalpthe valveis lifte from its seat so as to permit more rerigerat fluid to flow. Ifthe pressure in the expansion chamber is abnormal it may be that it willforce the pressure diaphragm back against the springs-and still hold thevalve to its seat. As more rerigerating fluid Hows past the valve to theexpansion coil and the tempe rature drops as a result of this theregulating fluid contracts and the, contraction of this Huid allows theexpansion diaphragmlto contract and ca use the valve to close unlessthere is an unusually low fluid pressure in the expansion chamber.

fluid, an expansion diaphragm controlling the opening and closing of thevalve, a diaphragm mounted to control the position of the expansiondiaphragm and subject to the ressure of the re rigerating fluid on theeX- 5o ansion side of the valve, and a thermostatc regulator connectedwith the expansion diaexpansion diaphragm, fled.

v il

hragm for contracting and expanding the substantially as speci- 5 2. A`refrigerating ap aratus having alve for controll' the ow of rerigerat'uid, a pressure diaphragm subject to the ressure of the refrigeratingfluid on the eX-' ansion side of the valve, an expansion diahragmlocated between and connected with oth the pressure diaphragm and thevalve,

and a thermal regulator connected with the expansion diaphragm for causmSlon and contractlon, substantla to thrust the pressure dia siondiaphragm located nected Withlboth the valve and the pressure diaphragm,and a th its expanly as specio 5 ed.

3. A refr' erat' a aratus havin a alve for xlonlrollinmgthelw ofrerigeraing uid, a pressurev diaphragm subject to the ressure of thererigerating fluid on the exansion side of the valve, a spring arrangedhragm against the ressure of the refrigeratmg fluid, an expanbetween andconermal regulator conected with and adapted to cause the eX- ansion andcontraction of the expansion iaphragm, substantially as specified.

ARTHUR H. EDDY.

Witnesses:

HARRY R. WILLIAMS', E'rrrEL M. LOWE.

